Prolonged passive vibration of Achilles and patellar tendons decreases effort perception during subsequent cycling tasks.

Abstract

BACKGROUND The perception of effort is a key determinant of endurance performance and a barrier to physical activity in inactive populations. From a neurophysiological viewpoint, effort perception is thought to arise from the brain processing of an efference copy of the motor command in sensory areas. However, recent research suggests that feedback from muscle spindles plays a significant role in this perception. In this study, tendon vibration protocols were employed to attenuate sensory feedback during subsequent cycling exercises. The aim was to assess whether vibration would increase cycling power output, muscle activation, and heart rate at fixed perceived effort intensities. METHODS Fifteen healthy young participants completed 2 experimental visits (vibration and sham). In each visit, participants performed two 3-min cycling bouts, 1 at a moderate perceived effort intensity and 1 at a strong perceived effort intensity, before (pre) and after (post) an actual or a sham vibration protocol. Vibration was applied bilaterally on the patellar and Achilles tendons for 10 min. Power output, heart rate, and vastus lateralis electromyography (VL EMG) were recorded and averaged for each bout. Absolute values as well as relative change (%) between pre and post conditions were compared across sham and vibration conditions. RESULTS At moderate perceived effort, power output, heart rate, and VL EMG increased post-vibration compared to pre-vibration (p < 0.05), while no difference was observed in the sham condition. At strong perceived effort, power output and VL EMG decreased post-sham (p < 0.05) but remained unchanged post-vibration. Moreover, the relative change between pre and post conditions was significantly higher in the vibration conditions compared to the sham condition for all variables. CONCLUSION This study shows that tendon vibration reduces effort perception during subsequent cycling bouts. This effect is likely a consequence of vibration-induced reduction in muscle spindle reafferent signaling to the brain, but this mechanism remains to be further elucidated. From an applied perspective, these findings highlight tendon vibration as a promising tool for enhancing physical activity engagement.